1. The problem statement, all variables and given/known data Calculate the mean spacing between hemoglobin molecules inside a red blood cell? 2. Relevant equations Diameter of red blood cell = 5 microns 3*10^8 hemoglobin molecules in each red blood cell Volume of hemoglobin molecule = 8.71*10^-26 m 3. The attempt at a solution I assume we take the blood cell to be a spherical model, therefore we can find the volume of the cell. I am having trouble understanding how to use this data to find spacing inside a sphere.